Devices using reflective light for examining the interior condition of a gun bore or barrel for wear, obstruction and other defects are well known. In general, such devices when placed in the receiving chamber of a firearm operate to transmit or refract light from an external source into the bore or barrel of a firearm and permit inspection from the muzzle end thereof. Over the years, sundry designs have evolved which employ various assemblies and materials to attain this common objective.
For example, one such device is disclosed in U.S. Pat. No. 2,403,452 issued Jul. 9, 1946 to Novak. In this arrangement, a bent piece of constant diameter, cylindrical, thermoplastic material is embedded in a block of metal held in the breech of gun. A related device is set forth in U.S. Pat. No. 3,228,108 issued Jan. 11, 1966 to Chaperon. Here, a combination bore sight and scope features a generally L-shaped, transparent material provided with a fused mirror. While devices of this type are generally satisfactory in accomplishing their basic goal, there remains a need to improve firearm inspection devices so that they will provide a better inspection quality, be more easily manufactured and be more positively handled, yet remain lightweight, durable and inexpensive.
Unlike prior art constructions which employed manually formed or bent Lucite or acrylic pipe, it would be preferable to seek a quality injection molded product utilizing a flowable material which has extremely high ultraviolet radiation absorption and a high refractive index to improve the transmission of light captured from an external source. In the same vein, it would be desirable to obtain a configuration which will optimize light gathering and distribution. It is further contemplated that, in the environment of firearm maintenance, gun powder and other surface residues could make the inspection device more difficult to handle so that provision should be made to enable a more positive handling of the inspection device. Moreover, the inspection device should remain simplistic in construction and use without dependency on batteries, switches, bulbs, wires and the like which compound the manufacturing and maintenance costs of some designs heretofore used.